1. Field of the Invention
The present invention relates to an imaging apparatus provided with a multiple exposure shooting function to combine a plurality of captured images.
2. Description of the Related Art
There are two methods for performing multiple exposure shooting. By one method, after shooting a scene a plurality of times, data from an image sensor is simply subjected to an addition process. By another method as discussed in Japanese Patent Application Laid-Open No. 2006-128740, after a division process is performed which reduces exposure by a number of shootings to be subjected to the addition process, the addition process is performed. In either case, the image data subjected to the addition process is developed, recorded in a recording medium, and the multiple exposure shooting is ended. In the latter method, even if a plurality of images is multiplexed, the images are averagely multiplied by a negative gain corresponding to a number of multiplexed images, so that the combined images are hard to be saturated or to fail.
However, in the conventional art as discussed in Japanese Patent Application Laid-Open No. 2006-128740, there is a case where a desired image is not obtained. For example, when multiple shooting of the moon above a nighttime mountain shown in FIG. 11A and a cloud on a daytime mountain shown in FIG. 11B is carried out and captured images are combined, combined images may not be a desired one. In the nature of things, a picture as shown in FIG. 11D is natural, which retains original brightness of the moon and cloud. However, in the conventional image processing method in the multiple shooting which uses the simple addition or the average addition, brightness of the moon and sky, or the sky, cloud and mountain mix with each other, so that a bit darkened and unnatural image is obtained.